Objective: To construct an eukaryotic expression vector of tumor associated gene tropomyosin 2 (TM2) tagged with green fluorescence protein and study its biological role in tumorigenesis. METHODS; Whole length of TM2 cDNA sequence was amplified from human gastric cancer cell line AGS by reverse transcript PCR. The recombinant TM2 was inserted into eukaryotic expression vector pIRES2 tagged with enhanced green fluorescence protein. pIRES2-EGFP was transfected into human hepatoma cell line QGY-7703 cells by liposome technique and detected by fluorescence microscopy and flow cytometry. TM2 protein level was determined by Western blot. The in vitro invasion and motility were further studied. Its tumorigenesis was assessed on nude mice.
Results: The recombinant TM2 was shown to be expressed in QGY-7703 cells by fluorescence microscopy and flow cytometry. The protein level of TM2 was increased. The invasion ability of TM2- transfected cells was increased(45.6 +/- 9.9) than that in controls(21.6 +/- 3.3, P < 0.05), as well as mobility(41.4 +/- 11.8 vs. 16.7 +/- 3.7). The tumor volume was (241.5 +/- 95.1) mm3, significantly higher than that in blank-vector controls (100.6 +/- 85.4) mm3 and negative-controls (123.7 +/- 92.3) mm3.
Conclusion: TM2 plays a role in growth and metastasis of hepatic tumor.